This proposal for supplementary funding, submitted under ARRA guidelines NOT-OD-09-058 (NIH Announces the Availability of Recovery Act Funds for Competitive Revision Applications) extends the scope of the parent Program Project grant. The overall effort centers on Neurospora crassa, a premier filamentous fungus model for over 250,000 species of non-yeast fungi. A primary goal is to understand how N. crassa transitions from mycelial growth to complete asexual spore development. We focus on two key triggers of asexual development, light and desiccation. In addition, we will leverage our prior successes to expand systematic knockouts to an additional prominent model system, Aspergillus nidulans. Neurospora and Aspergillus are salient models for basic research in eukaryotes;fungi allied to these species include most animal and plant pathogens as well as industrial strains yielding chemicals, enzymes, and pharmaceuticals. Over the first 5 years of prior support we revolutionized the technology for gene knockouts in filamentous fungi, exceeding our initial target by >50%. Project #1 completes Neurospora gene knockouts and extends systematic disruptions to Aspergillus. In support of the overarching goal of understanding regulatory pathways governing filamentous fungal development, in Projects #2 and #3, knockout and knock-ins are created via high throughput techniques. The Project #1 Supplement creates a new Aspergillus aim focused on proteomic analyses to describe the composition and location of intracellular complexes, while completing knockout cassettes for 1242 genes added to the Aspergillus genome since the parent grant was submitted. In the parent grant Projects #2 and #3 will describe and reconstruct the regulatory cascade that underlies N. crassa's developmental response to light and air, from the level of chromatin structure through the gene regulatory network, via ChlP-seq mapping of histone modifications, transcription factor binding sites, and epigenetic marks, correlating these with transcriptome measurements to generate a deep description of genome and epigenome dynamics. The Supplement to Project #3 expands the scope of this considerably by incorporating two new investigators and an alternative approach that has identified additional regulators. In terms of the ARRA, the supplements expand the scope of the original aims by adding projects that will vastly accelerate the pace ofthe work and that can be completed within 2 years. They allow for job creation and retention by adding a junior faculty New Investigator not yet supported by the NIH, employing an unemployed technician, three unemployed postdocs, two graduate students, restoring to full employment another postdoc, and making substantial purchases of US-made supplies and equipment. PUBLIC HEALTH REVELANCE: Filamentous fungi, typically known as molds, are common animal and plant pathogens, but they are also widely used as industrial strains to provide antibiotics, chemicals, enzymes, and pharmaceuticals. We'd be dead without them but they can kill us. We seek to understand how genes and proteins work together to regulate fungal growth and development, so as to enhance the good things and control the bad things produced by fungi. This supplement would support an NIH New Investigator, and employ or restore to full employment a technician, four postdocs, and two students.